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Allushta [10]
2 years ago
7

Solve by factorization 2x^2 + 3x -20 = 0

Mathematics
2 answers:
saul85 [17]2 years ago
4 0

Answer:

x=2.5 or x=-4

Step-by-step explanation:

factorisation= factors:1, 2, 4, 5, 10, 20 (only the positive factors)

We will use the factors 4 and 5.

=(2x-5)(x+4)=0

2x-5=0   || x+4=0

2x=+5      || x=-4

x=2.5  or x=-4

Hatshy [7]2 years ago
3 0

Answer:

x = 5/2, -4.

Step-by-step explanation:

2x^2 + 3x - 20            

NOTE:  2 * -20 = -40 so we need 2 numbers whose product is - 40 and whose sum is + 3.  These are + 8 and -5, so we write

= 2x^2 + 8x - 5x - 20     Factor by grouping:

= 2x(x + 4) - 5(x + 4)

= (2x - 5)(x + 4)

so x = 5/2, -4 are the roots.

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Can you explain how to do 13 please
Zigmanuir [339]
I must confess that I was about to pass this question by, but I was captured by the respectful and dignified way in which you asked for help. 

A careful reading of the problem gives you two equations in two unknowns, which you can then solve as simultaneous equations.  Here's how it looks:

Call 'C' the price of the senior <u>C</u>itizen ticket.
Call 'S' the price of the <u>S</u>tudent ticket.

On the first night . . .    10 C  +  12 S  =  208

On the second night . . .  8C  +  3 S  =  74

Those are your two simultaneous equations. Now the idea is to multiply or divide each side of one equation in such a way that when you add or subtract it from the other equation, one of the variables will become a zero quantity ...  you'll be left with an equation in one variable, which you can easily solve. THEN, knowing the value of one variable, you can put it back into one of the original equations,and find the value of the other variable.

This all sounds more complicated than it is.   Here's how it goes:
We have . . .

10 C  +  12 S  =  208  and
8C  +  3 S  =  74

I'm going to multiply each side of the second equation by  4, and then write it under the first one:

10 C  +  12 S  =  208
32 C  +  12 S  =  296

Now, subtract the lower equation from the upper one, and you get . . .

- 22 C  +  0  =   - 88

Divide each side of this one by  -22  and you have    <em>C = $4.00</em> .

THAT's what you need, to blow the whole problem wide open.  Knowing
the value of 'C', let's substitute it into the equation for the first night:

10 C  +  12 S  =  208

10(4)  +  12 S  =  208

40  +  12 S  =  208

Subtract  40  from each side :    12 S  =  168

Divide each side by  12 :    <em>S  =</em><em>  $ 14.00 </em>.

Finally, as we look over our results, and see that Students have to pay  $14  to see the show but Seniors can get in for only  $4 , we reflect on this ... or at least I do ... and realize that getting old is not necessarily all bad.
3 0
3 years ago
PLEASE HELP!!!
pogonyaev

Step-by-step explanation:

Part A:

Let m be the number of mittens and s be the number of scarves. Then we have the inequalities:

s+m\leq 30. <em>This says Nivyana and Ana cannot make more than 30 scarves</em>

50s+25m\geq 1000. <em>This says that</em> <em>Nivyana and Ana have to earn at least $1000.</em>

Part B:

The graph is attached.

Notice that the graphs of the inequalities are solid lines, this just means that the points on these lines included to the solutions of each inequality.

The darker shaded region and the solid lines bounding it, are the solutions to the inequalities because that's where the values common to both inequalities are found.

Part C:

From the graph we get two possible solutions:

15 scarves & 10 mittens

25 scarves & 5 mittens.

These two points lie on the solid lines that bound the darker shaded region<em> (I picked those points to stress that the lines bounding the dark region are also solutions.)</em>

8 0
2 years ago
Find two pairs of integers whose sum is -6
aalyn [17]
<span>Find all pairs of consecutive even integers whose sum is greater than 73 but less than 79.

</span>
6 0
2 years ago
Read 2 more answers
Is 160 greater or less than 2 1/2
stich3 [128]

Answer:

greater than

Step-by-step explanation:

On a number line 160 is further to the right than 2 1/2

8 0
3 years ago
I need help with<br> If x = 5, find the value of LaTeX: 16-x16 − x
Nina [5.8K]

Answer:

-69

Step-by-step explanation:

16-(5)(16)-(5)

16x5=80

16-80-5

16-80=-64

-64-5=-69

3 0
3 years ago
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